Scratch on my refractor objective.....

[Higgs_Bozon]

I got a Orion Short tube CT80 recently for like half the market price( I guess I know why lol), and there's a pretty noticeable problem on the objective lens. It looks like a scratch and it's not on the surface, it kinda looks like it's under the lens....

Will it affect picture quality much or viewing quality?

[Franklin]

Looks like it could possibly be a hair on the inside of the lens. The cell unscrews from the tube, then use a bulb blower to blow off the dust etc from the rear of the objective.

[ollypenrice]

It will probably have no visible effect whatever, though it might just create a slight diffraction spike on brighter stars. If it does, try covering it (on the outside) with something black, like a small piece of electrical tape or black paint. Avoid straght lines on this tiny  blackout patch.  If this seems odd, remember that many telescopes have large, opaque obstructions slap in the middle of the objective.  Ours, for instance...

The obstruction is far too far out of focus to form an image.

Olly

[blinky]

yeah, I would not worry about, be happy you got a half price scope!  I doubt even if you pixel peep, if you would be able to tell

[dweller25]

Hello @Higgs_Bozon and welcome to SGL.

That “scratch” (it could be lint) will have no effect whatsoever on the views and if you got the scope for half price because of it then you got a great deal 👍

Edited October 28, 2023 by dweller25

[athornett]

I agree- it won't make ANY difference to the views at night possibly a nuisance of you ate solar viewing (with appropriate filters)

Andy

[F15Rules]

As above, no problem, just enjoy the views!👍

Dave

[Louis D]

It takes a lot of crud on an objective to become noticeable.  This is nowhere close to that level.

[The Lapwing]

17 hours ago, Louis D said:

It takes a lot of crud on an objective to become noticeable.  This is nowhere close to that level.

Like he said, enjoy 

[jock1958]

On 28/10/2023 at 15:46, Franklin said:

Looks like it could possibly be a hair on the inside of the lens. The cell unscrews from the tube, then use a bulb blower to blow off the dust etc from the rear of the objective.

Agree with you it doesn’t look like a scratch and if it unscrews without knocking out the collimation I would be very tempted to do as you suggest with bulb blower. I know you should look through it and not at it but I’m Mr OCD 🤣

[Franklin]

3 minutes ago, jock1958 said:

if it unscrews without knocking out the collimation

Unscrewing the whole cell from the tube will not effect collimation, just be careful when re-threading it back on as the threads are fine and can be easily cross-threaded. Don't over tighten, just nudge it back into place.

[Higgs_Bozon]

Thank you to everyone for helping!